The present invention relates to a drive device for locking and unlocking a lock with conditional opening.
More particularly the invention relates to the application of this device to a time lock known as a high security lock, for controlling access during specified time ranges to high security enclosures, such as strong boxes or strongrooms for example of banking organisations. The invention thus also concerns the application of this device to high security enclosures, such as strong boxes or strongrooms.
One such device and a time lock of this type are described in the patent EP 0 256 430.
A security system described in this document and incorporating this device and this lock is shown in very schematic manner in FIGS. 1a and 1b for explanatory purposes.
As described in this document and as shown in FIG. 1a, the closure of a door PO of a strong box or of any other high security enclosure (this door being viewed from the inside in FIG. 1a) generally takes place with the aid of several bolts PT controlled by a linkage TR, this linkage being adapted to be shifted by an operator with the aid of a wheel VO from a locked position to an unlocked position and conversely.
To this end, the linkage TR comprises a bar B which controls the movement of the bolts PT of the door PO and which is coupled to the wheel VO through a mechanism of rack and pinion type.
This bar B can be shifted in translation under the action of the wheel VO to effect the displacement of the bolts PT and to take care of the operations of locking (bolts extended) and unlocking (bolts retracted).
In order to prevent opening of the door PO and to hold the linkage TR in the locking position when the bolts PT are in this position, this system comprises a first lock S which is itself provided with a bolt PS for engagement in the bar B. The bolt PS is thus provided to prevent the movement in translation of the bar B.
This first lock S can be controlled in the simplest version by a key or equally by more sophisticated means, such as a magnetic card, a smart card or an electronic system operating with a code or other type of authorisation for access.
However, in order to enhance the degree of security and to prevent any fraudulent use of this first lock S, a second lock SH called a time lock is associated therewith.
This time lock SH also has his own bolt PV which is called more generally the locking bolt or block and which is arranged to be positioned in the path of the bar B in order to obstruct its movement towards the unlocking position. In the raised position of the block PV shown in FIG. 1a, the bar B comes into abutment with its rear end against the block PV.
The locking block PV is associated in this time lock SH with a drive device DEN, comprising in particular (FIG. 1b) an electromagnetic motor MEL and a mechanism MCL comprising a cam CA arranged to drive a lever LE.
Thus in normal operation, the locking block PV can occupy a high position, called the active position and shown in FIG. 1a, preventing movement of the bar B and blocking the door PO of the enclosure.
The block PV can be moved down into a low position called the inactive position (FIG. 1b), by lowering the lever LE, under the action of the motor MEL. In this low position of the block PV, the bar B can be retracted, in order to disengage the bolts PT of the linkage TR. The path of the bar B is thus freed to allow the door to be opened.
This drive device DEN can be controlled by electronic means EL (FIG. 1a) associated with display PA and data entry ED peripherals used for programming the time ranges. The peripherals PA and ED are formed in this example by a digital display and a keypad. The electronic means EL further comprise a microprocessor MP and a memory MM of RAM/ROM type, the microprocessor MP providing control signals, on the basis of the program stored in the memory MM, which pass through an amplifier AMP to the drive device DEN.
Accordingly it is possible with this arrangement to programme periods of time during which the locking block PV will prevent the bar B sliding, even if the opening of the first lock S is prescribed by an authorisation signal recognised as valid, i.e. by a key or a valid opening code.
Accordingly, by using this time lock SH, the security is doubled, by preventing even the authorised personnel in possession of the key or the code for the enclosure from effecting any opening in one or more judiciously chosen ranges of time.
FIG. 1b shows in more detail the drive device DEN which is described in the above-mentioned document EP 0 256 430. It will be seen that the locking block PV is associated with a compression spring R which is supported by a rod TG driven by the drive device DEN.
More particularly, the block PV has a longitudinal recess into which the rod TG slides, being retained by a screw.
The rod TG has a collar on its base, the spring TG being interposed between this flange and the base of the block PV. Thus, in this device, any angular movement of the cam CA under the control of the motor MEL effects rising or falling movement of the block PV, through the spring R which is mounted between the block PV and the transmission device formed by the rod TG, the lever LE and the cam CA.
If the bar B is in the path of the block PV when the block rises, the spring R is compressed under the action of the mechanism MCL, which continues its course under the drive of the motor MEL. The block PV will be able to occupy its high, active position at the instant at which the bar B is shifted into its locking position, towards the right in this example. The spring R will then give the block PV the energy which it has stored, so that the block PV finishes its course in its turn and comes to block the path of the bar B. It will be understood that this device is single action.
There also exist more complex devices with a double action, comprising a second spring fitted into the rod, which has a telescopic structure. The second spring is intended to allow the drive device to finish its course when the block PV is blocked in the high position by the bar, which abuts laterally against it and wedges it in the slide of the bar B.
This device allows the desired result to be achieved.
However, it has several disadvantages.
Thus it requires implementation of a cam, and the arrangement of two springs in the double acting version and the formation of a complex hollow rod. It is also necessary to form a passage in the locking block.
Moreover, and with reference to FIG. 1b, it is noted that the time lock described in the document EP 0 256 430 comprises an inhibit device INH which allows the function of the time lock to be blocked, in the case of a breakdown and through a special procedure.
The inhibit device INH thus allows the locking block PV to be moved, against the force of the spring R, from its active, high position (FIG. 1a) towards its low position, in which it is inactive, in order to allow the shift of the bar B and allow opening of the door PO, in order to effect the repair or repairs needed on the time lock.
When applied to a high security enclosure, such as a strong box or a strongroom, the time lock SH is disposed and arranged on the door so as to be inviolable. It is generally inaccessible from outside the enclosure.
However, any malfunction of the time lock SH when the locking block PV is in its raised position causes the bar B to be blocked. A malfunction of this type which occurs during the normal hours of opening of the enclosure seals off the door for good. The time lock SH is inaccessible to security staff and the only remedy is to destroy the door or one of the walls of the enclosure by making a hole in the wall. This type of intervention is expensive and makes the strong box or strongroom unusable for several days, even several weeks.
The inhibit device INH makes it possible to avoid this type of intervention. The device allows the bar to be unblocked, by retracting the locking block PV by an exception procedure which can be controlled from outside the enclosure. Thus, the inhibit device INH is arranged so that it can push the locking block PV down, even though the block is subjected to the bias of the compressing spring R, which tends to push it up.
As a result, it is seen that in this type of high security installation it is necessary so to arrange the drive device DEN that it allows return of the locking block PV to its inactive position, in the case of breakdown, even if the block PV is held in its active locking position by the drive device DEN.
The drive device DEN should thus be designed to allow the drive action of the inhibit device INH on the locking block PV, in the case in which this inhibit device has to move the locking block PV against the force of the spring R, in order to render this block temporarily inoperative. This arrangement must thus be reversible.
U.S. Pat. No. 4,633,687 describes a drive mechanism of a lock which can be controlled by a key. This lock is used for locking the door of a hotel in which a combined closing system is used, formed by an electronic key and a purely mechanical key associated with a card which can issue a code which can be read and processed electronically.
This mechanism comprises a control device for an auxiliary bolt, which is provided to engage in a recess formed in a disc, this disc being connected to rotate with a shaft, whose rotation which is normally effected by the key, enables the retraction of the main bolts of the door, to open it.
This control device comprises a motor which can be controlled by an electronic circuit and which can drive a toothed wheel, coupled mechanically to the auxiliary bolt through a spring and an eccentric mechanism.
This eccentric mechanism comprises a finger or lug which can slide inside an oblong groove to effect the translation of the auxiliary bolt into the recess of the disc and out of this.
Although this arrangement is compact and it avoids fitting one or more compression springs of the type of those described in the document EP 0 256 430 mentioned above, the arrangement suffers from several problems.
Thus this arrangement is provided for a traditional application to a house door. It is not adapted for application to high security locks. Thus it is noted that its eccentric mechanism does not allow the auxiliary bolt to be returned to the inactive position when it is extended at the end of its course. This arrangement is thus not reversible.
The object of the present invention is to deal with these problems by providing a compact drive device with a simple structure, which can ensure reversible movement of the locking block or bolt for unlocking the security enclosure, in particular in the case of malfunctioning.
To this end the invention provides a drive device in particular for locking a conditionally opening lock, the device comprising:
motor means with a drive element having a first axis of rotation,
a transmission arm having first and second ends, this arm being mounted pivotally at its second end, about a second axis of rotation distinct from the first axis, this arm being provided with a coupling surface formed in the vicinity of the first end,
a locking block connected mechanically to the motor means by means of the transmission arm, this arm being operable by the motor means to cause the block to occupy an active position, in which it opposes the displacement of a bar, and an inactive position in which it allows displacement thereof, and
elastic means allowing the locking block to be put under bias when it is actuated by the motor means, in particular towards its active position and when its displacement is impeded by the bar, characterized in that the elastic means are arranged between the drive element and the transmission arm, these elastic means being in direct driving contact with the coupling surface of the transmission arm.
The invention also provides a drive device for in particular locking a conditionally opening lock, the device comprising:
motor means with a drive element,
a transmission member provided with a coupling surface,
a locking block connected mechanically to the motor means by means of the transmission member, this member being operable by the motor means to cause the block to occupy an active position, in which it opposes the displacement of a bar, and an inactive position in which it allows displacement thereof, and
elastic means allowing the locking block to be put under bias when it is actuated by the motor means, in particular towards it active position and when its displacement is impeded by the bar, characterized in that the elastic means are arranged between the drive element and the transmission member, the transmission member being connected to the locking block through a rod or link which is articulated to the locking block.